Thursday, 26 November 2020

A fresh display from Rovaniemi

No more drawer displays from Rovaniemi this is from the early morning of last Saturday, 20 November! 

On the eve of action the sky cleared up soon after midday, but wind remained strong. I kept checking the weather station graphs and the habit of the power plant plume that is visible from my window. At around 3 am the signs were such that it was better to go. 

When I arrived to the ski center on the other side of Ounasvaara, the action was already on: nice tangent arcs above the bright slope and ski jump floodlights. But the stuff was just hanging around the guns, no good for the spotlight there because of the excess light pollution. 

So I waited. At around 5 am the diamond dust took finally off, reaching towards the city. I followed, getting stoked by the lower tangent arcs that swept by under each streetlight as I drove. About a halfway to the city center I took off from the main road and went to a place for small boats by the river.

Because of the tight space there I had to place the lamp pretty close to the camera. It is about 9 degrees below the horizon. The lamp is the same old 75W HID that I used four years ago. I have another light with very tight beam that I hope to try soon. 

A HaloPoint simulation is included. As usual, I was not able to get it right. Once some detail got perfected, another worsened. That's how it goes. The sub-120 parhelia are rather weak in the photo, but when I viewed them from the side of the beam, they were quite striking. I think in the center of the beam where the camera was, a visual would have been impossible.

Sunday, 1 November 2020

One more case of sub-Kern companion arcs

Sometimes a sub-Kern arc "bleeds": it is accompanied by thin arcs below the brightest parts. The first case we photographed on the night of 6/7 January 2016 and second on 28/29 November 2016, both in Rovaniemi. Here is a third display with these arcs in Rovaniemi, photographed on the night of 4/5 January 2017. The lamp is somewhere between 5 and 10 degrees below the horizon. The temperature at this roadside field was -38 C, the lowest I experienced that winter. Earlier that night, at another location, I had photographed odd radius sub-plate arcs.


Below are three more photos from that location, taken before the the sub-Kern company arcs appeared.